Continuously adjustable control device for automatic vacuum cleaners



Spt; 25-1956" Filed May 11, 1954 2 Sheets-Sheet l 5% INVENTOR OLIKEE L. 045

Sept. 25, 1956 o. ALLEN 2,764,256

commuousu ADJUSTABLE CONTROL DEVICE FOR AUTOMATIC VACUUM CLEANERS Filed May 11, 1954 2 Sheets-Sheet 2 INVENTOR UL/VEE LIHLLlS/V fzf RN EY fi lce 2,764,256

CONTINUOUSLY ADJUSTABLE CONTROL DE- VICE FOR AUTOMATIC VACUUM CLEANERS Oliver L. Allen, Riverside, Conn, assignor to Electrolux Corporation, Old Greenwich, Coma, a corporation of Delaware Application May 11, 1954, Serial No. 428,969

6 Claims. (Cl. 183-37) This invention relates to vacuum cleaners and more particularly to such cleaners as have automatic means for controlling certain desirable functional operations of the cleaner in accordance with predeterminable variations in air pressure resulting from dust and dirt collected therein during use.

-It is a major object of this invention to provide an adjustable control device which enables an operator of the vacuum cleaner to set in advance, as on a dial, the differential pressure variations at which automatic responses take place within the cleaner. Among such responses may be the actuation of a valve for controlling the admission of vacuum or pressure to a power diaphragm. This power diaphragm may in turn be used to wall of 30 and is biased to open position by spring 38. A hose coupling assembly 42 is pivotally mounted by pins 44 in the opening 40, Fig. 2, formed in the cover. Link 48 pivotally connected to the hose coupling assembly at one end and to a projection 32 at the other end forms a parallel motion linkage which causes the hose coupling assembly 42 to move parallel to itself throughout the opening and closing of the cover 34.

Hose coupling assembly 42 velfects an airtight seal with front body ring 26 by means of the stiff cardboard disc 58 of dust bag or-dust separating member 56 with the aid of flexible .gasket 54 hearing against the disc and holding the edges thereof against sealing ring gasket 60 carried by front body ring 26. Tubular member 52 of hose coupling assembly 42 extends through a centrally disposed opening in disc 58 when the cover is in the closed position shown in Fig. 1, in order to introduce the air and entrained dust directly into the interior of dust bag 56.

The electrical and pneumatic control units are operatively interrelated. The pneumatically operated power diaphragm device 250 consists of a large upwardly spring deerengize the vacuum cleaner motor fan unit, open the front cover, eject the dust container or merely cause the operation of a visible or audible signal.

It is a further and important object hereof to provide asimple control device, accessible from the exterior of the cleaner body and enabling the operator to adjust the point at which the pressure differential within the cleaner opens the valve at any one of a number of predeterminable values suitable for fine dust, coarse dust, fluffy materials, etc. This is effected by providing a screw threaded member which may be raised or lowered at will to cooperate with a tension or pressure spring so as to result in a faster or slower diaphragm operation.

Still other and further objects and additional advan-' tages of this invention will become evident to those skilled in the art upon consideration of the following description together with the accompanying drawings wherein:

; Figure 1 is a side view, partly in section and with portions broken away to show details of construction of a.

vacuum cleaner embodying this invention;

Figure 2 is a top plan view, somewhat enlarged, of the control unit and front cover in open position for use with the vacuum cleaner of Fig. 1;

Figure 3 is a cross-section, somewhat enlarged, taken on the line 33 of Fig. 2; and

'Figure 4 is a cross-section taken on the line 4--4 of Fig. 2 showing a detail of the power diaphragm linkage.

Referring now in more detail to the drawings, elongated biased diaphragm which is operatively connected to the high suction side of the vacuum cleaner chamber by conduit 255, the top chamber 220, Fig. 3, perforations in the supporting ring 242 of valve 240, center opening 202a in casing 202, upper chamber 205 of a pressure differential measuring device and conduit 225 to the opening 230, Fig. 2, in the inner sealed chamber 40.

The pneumatic system includes a pressure differential measuring device (lower half of 200 below casing 202) which initiates the lifting of valve 240 and combined therewith is an auxiliary valve lifting membrane 270 (upper half of 200 above casing 202) which completes the opening of valve 240 and holds it open until power diaphragm 250 completes its work. The lower half of unit 200 comprises a pressure differential measuring control device, Fig. 3, having a lower casing 201 and an upper casing 202, separated by a diaphragm 203. The space in the lower casing below diaphragm 203 is connected by communicating conduit 210, Figs. 2 and 3, to

opening 215 on the dirty or dust collecting side of the which is compressed between the flared end of a spring holder 304 depending from the center of the diaphragm and an annular shoulder formed in a threaded sleeve 302.

The upper half of unit 200 comprises an auxiliary valve lifting device having a lower casing 202 and an I upper casing 204, separated by a diaphragm 270 having a body or cleaner housing 10, is appropriately supported on a'pair of runners 12. A motor fan unit comprising a fan 14 and an electric motor 16 is mounted by airtight Partition or bulkhead 18 within the posterior portion of body 10. Fan inlet 20 draws air by suction through the space within body 10 which contains inner body or dust bag receiving compartment 22 perforated with apertures 24 for free passage of suction air current therethrough. Inner body 22 is secured at one end to front body ring 26 which in turn is secured within the open anterior end of outer body-10.

Suspended from the lower part of ring 26 and attached thereto by suitable fastening means such as bolts 28, Fig. 2, is control chamber 30. Front cover 34 is hinged by pin 36 to a pair of projections 32 extending from the front fixed periphery and a fixed perforated center portion through which valve 240 moves. normally to closed position by a spring 240a. Valve stem 241 is of fixed height and its opening is initiated by dia- 254, Figs. 2 and 4 With this device, membrane 270 (open on its lower surface to the atmosphere through opening 202b and subject upon the opening of valve 240 to high suction on its upper surface) assures the completion of the operating cycle including the release of both pin 70 and the latch by maintaining valve 240 in wide open position through a lifting action exerted on the outer edges of valve supporting ring 242 by the upwardly distended diaphragm 270 (see'Fig. 3).

With the opening of front endassembly 34, the discharge of the bag and the slowing down of the motor fan Patented Sept. 25, 1956'.

Valve 240 is biased unit; atmospheric pressure is reestablished on both sides of. each. of. diaphragms. 203 and. 270. which are returned to their original positions under the biasing action of springs 203a and 24%, respectively.

The electricalsystemfor energizing, themotor fan unit" and the electrical controls. are of the conventional form and hence neednot be specifically described.

In detailandparticularly with respect to theoperationof. the pneumatic and electrical controls and referring especially to Figs. 2 and. 3, Where details of structure are illustrated, the force exerted on the pressure differential diaphragm 203 progressively increases with continued dustcollection, untilit attains sutficient value to displace thediaphragm upwardly against the resistance. of spring 203a-.until" stem 241. is lifted to slightly open valve 240, whereuponhigh suction is applied to the upper surface of diaphragm 270 and permits atmospheric pressure to fully open valve 240 and to hold it open. This allows high suction to operatepneumatically functioning device 250 which.v in turn through link 254 and latch pinrelease arm. 75, etc., selectively positions pin 70 so that pin 70 is prevented from relatching by being overridden. by the under. side of superpositioned latch bar 63.- The actual release and ejection of the dust bag 56 is subsequently effected by the more substantial movement or more complete opening of cover 34 the lug 160 of which finally releases switch deenergizing mechanism 113. The decelerating motor fan. unit causes a drop in the suction air current. This. frees latch bar 63 for further forward travel, causes. latchspring 62 to ride down the inclined edge 56b of cam bracket. 560 to release lug 52b holding ejection plate 52.

Thus, substantially simultaneously with the withdrawal of pin. 70, release arm 75, Fig. 2, trips cover releasing latch 100 which holds cover assembly 34 closed against spring tension. The release of cover 34 first breaks a circuit at the contact points of switch 310, Fig. l, by a lug 16c releasing sliding mechanism 113 which latter is biased by spring 114 to throw switch 310 to off position, thereby deenergizing the motor fan unit. Thereafter, the front cover continues its opening movement, moving substantially 90, while the suction air current drops sufficiently to release the bag ejector mechanism 51 through a previously traced series of steps, allowing the bag ejector plate 52, Fig. 1, to push the bag forward and throw the bag audits contained dirt out of the cleaner casing.

In accordance with the improved control device. of: this invention, means is provided for adjusting the pressure on sprmg 203a with the aid. of an internallythreaded knob 300 cooperating. with the externally threaded sleeve 302 having a hollow center bore in which is compressed the spring 203a. The other end of spring 203a presses against the flared end of cup shaped spring holder 304 whichin turn is. afixed to the bottom of control diaphragm 203.

Thus, the rotation of knob 300, which is held in place on lower-casting 201 by retaining plate 306 and appropriate fastening screws and is sealed thereagainst by sealingring 308, causes sleeve 302 to either increase or decrease the compression of spring 203a. By this adjustment, the differential pressure at which diaphragm 203 contacts and actuates valve stem 241 can be adjusted from the exterior of casing 30. Increasing the compression of spring 203a results. in increasing the differential pressure necessary to be established by dust collection within the cleanerbag in order to enable diaphragm 203 to contact valve stem 241 and open valve 240. Thiscauses actuation of the power diaphragm 250 and results in. anyone of a number of subsequent steps, such as opening the cover, sounding of an audible or visualsignal, ejection, of the dust bag, etc,

Thus, with this type of structure, an operator is readily able to vary the spring load to any desirable limit and thus-.predeterminethe point at which valve 240 opens and automatic operation takes effect, since knob 300 is shown extending through an opening in casing-30,- Fig; 1, and hence is readily accessible to the operator for adjustrnent.

The various details forming the elements of the ejector system, the latching system, etc., among other structural elements not being a part of this particular invention may be readily understood by those skilled in the related art by referring to various other applications and Letters Patent among which may specifically be cited U. S. Patent pressure drop of air passing through said dust separating member, valve means operable by a predeterminedmovement of said diaphragm for controlling flow of air between said pneumatically actuated element and said means for producing flow, a spring for resisting movement of said diaphragm in the direction causing operation of said valve, and manually operable means for varying the tension of said spring.

2. In combination with a vacuum cleaner having a casing, a dust separating member and means for producing flow of. air' therethrough disposed in said casing, a pneumatically actuatedelement for controlling the operation of said cleaner, a housing, a differential pressure diaphragm dividing said housing into a high suction chamber and a low suction chamber, means for connecting said high suction chamber to a point in said casing between. said dust separating member and the flow producing means, means for connecting said 10w suction chamber to a point-in said casing ahead of said dust separating member, valve means operable by a predetermined movement of said diaphragm for controlling flow of air between said pneumatically actuated element and said flow producing means, a spring disposed in said low suction chamber for resisting movement of said diaphragm in the direction. causing operation of said valve, and

manually operable means for varying. the tension of said spring.

3. In combination with a vacuum cleaner having a casing enclosing dust separating means and suction pro-- ducing. means for causing flow of air therethrough, a pneumatically actuated element for controlling the operation of said cleaner, a housing, a diaphragm dividing said housing into a low suction chamber and a high suction chamber, conduit means for connecting said high suction chamber to a point in said casing between said dust separating means and said suction producing means, conduit means for connecting said 10w suction chamber with a point in said casing ahead of said dust separating means,

a spring retainer secured to said diaphragm and extending into said low suction chamber, an abutment disposed in said low suction chamber, a spring compressed between said retainerand said abutment, and means operable from the. exterior of said low suction chamber for changing the position of said abutment to alter the compression of. said spring.

4. In combination with a vacuum cleaner having a casing,.a dust separating member and means for producing flow of air therethrough disposed in said casing, a pneumatically actuated element for controlling the operation. of

said cleaner, a housing disposed underneath said casing,

a differential pressure diaphragm dividing said housing into an upper high suction chamber and a lower low suc:

tion chamber, means for-connecting said high suction chamber to a point in said casing between said dust sepa-.;

rating member and the flow producing means, means for connecting said low suction chamber to a point in said casing ahead of said dust separating member, valve means operable by a predetermined movement of said diaphragm for controlling flow of air between said pneumatically actuated element and said flow producing means, a spring disposed in said low suction chamber for resisting movement of said diaphragm in the direction causing operation of said valve, and manually operable means extending through the bottom wall of said housing from within said lower chamber for varying the tension of said spring.

5. In combination with a vacuum cleaner having a casing enclosing a dust separating member and means for producing flow of air therethrough disposed in said casing, a pneumatically actuated element for controlling the operation of said cleaner, a differential pressure diaphragm movable in response to variations in pressure drop of air passing through said dust separating member, valve means operable by a predetermined movement of said diaphragm for controlling flow of air between said pneumatically actuated element and said means for producing flow, a spring for resisting movement of said diaphragm in the direction causing operation of said valve, manually operable means for varying the tension of said spring, and an auxiliary assist diaphragm associated with said valve means and effective upon the opening of said valve to hold said valve in its open position.

6. In combination with a vacuum cleaner having a casing, a dust separating member and means for producing flow of air therethrough disposed in said casing, a pneumatically actuated element for controlling the operation of said cleaner, a housing, a diiferential pressure diaphragm dividing said housing into a high suction chamber and a low suction chamber, means for connecting said high suction chamber to a point in said casing between said dust separating member and the flow producing means, means for connecting said low suction chamber to a point in said casing ahead of said dust separating member, valve means operable by a predetermined movement of said diaphragm for controlling flow of air between said pneumatically actuated element and said flow producing means, a spring disposed in said low suction chamber for resisting movement of said diaphragm in the direction causing operation of said valve, manually operable means for varying the tension of said spring, and an auxiliary assist diaphragm associated with said valve means and effective upon the opening of said valve to hold said valve in its open position.

References Cited in the file of this patent UNITED STATES PATENTS 2,466,441 Keller Apr. 5, 1949 2,569,222 Beede et al. Sept. 25, 1951 2,622,399 Babitch Dec. 23, 1952 

